Implementation of an Outdoor Far-Field Measurement System at IRCTR (International Research Centre for Telecommunications-Transmission and Radar)

The IRCTR has developed and implemented several antenna measurement systems (far-field, near field, in both frequency and time domains) in its indoor test range. However the dimensions of this anechoic chamber do not allow for measurements on large antennas. Therefore an outdoor far-field antenna measurement system has recently been implemented on the roof of the building. Related test sets and circuitry were developed at IRCTR. This paper gives a description of the RF and mechanical subsystems as well as the data acquisition software. Measurement results of a three meter diameter S-Band parabolic reflector antenna - to be used in the TARA system (Transportable Atmospheric Radar) - which show good agreement with the computed radiation patterns are presented.